This invention relates to a unique carrier and differential assembly configuration for a drive axle.
Drive axles include carriers with differential gear assemblies to prevent wheel skid during turning maneuvers. When a vehicle travels along a straight-line path, both sets of wheels on a drive axle will turn at basically the same speed. During a turning maneuver, however, the wheels on the outside of the turn must travel a greater distance than the wheels on the inside of the turn, which means that the wheels on the outside of the turn must rotate at a faster speed than the wheels on the inside of the turn. A differential gear assembly is required to allow for this difference in wheel speed.
Traditionally, a drive axle carrier includes a ring and pinion gear input that is operably coupled to the differential assembly. The pinion is supported on a pinion shaft by a pair of tapered roller bearings on one side of the pinion gear and by a spigot bearing on the opposite side of the pinion gear. The differential assembly includes a first differential case half, a second differential case half, and a differential gear set. The ring gear is bolted to one of the case halves to define a first bolted joint and the first and second case halves are bolted together to define a second bolted joint.
This traditional pinion bearing support and differential case configuration is expensive to manufacture and difficult to assemble. Also, with the increased demand by users to provide more robust designs within the same packaging space, these traditional configurations do not provide room to make critical components more robust within the existing package.
Accordingly, it is desirable to provide an improved carrier with a differential assembly that includes a more robust component configuration within the same package. Further, it is desirable to provide a simplified carrier configuration that reduces the overall number of required components and is less expensive to manufacture, as well as overcoming the other deficiencies in the art outlined above.
A drive axle includes a carrier with a differential assembly. A pinion gear, operably coupled to a driving input, is in meshing engagement with a ring gear for rotation relative to a carrier housing. The differential assembly includes first and second differential case halves attachable at a case interface to define a case split line. The differential assembly also includes a differential gear assembly supported by the first and second differential case halves with the gear assembly being operably coupled to drive a pair of laterally spaced wheels. In the preferred embodiment, the ring gear, first case half, and second case half are all connected together via a single bolted joint with the case split line being located behind the ring gear.
Further, the differential case halves are each supported by a single differential bearing assembly. Each differential bearing assembly is installed between the respective differential case half and an adjusting ring. The differential bearings are mounted in a reverse configuration with the bearing cups being pressed into the differential case half and the cones being pressed onto the adjusting rings such that the bearing apexes diverge from one another. This bearing configuration provides increased stability.
In one disclosed embodiment, the pinion gear is supported on a pinion shaft between a pair of bearings. Preferably, the bearings are tapered roller bearings that provide the sole rotational support for the pinion shaft. A pinion cage has a first piece that supports one of the bearings and a second piece that supports the other bearing. The first piece is preferably threadably attached to the second piece to simplify the setting of preload.
The subject invention provides an improved carrier with differential assembly that significantly reduces the number of required components, improves and simplifies assembly, as well as providing a more robust design within a traditionally sized packaging envelope. These and other features of the present invention can be best understood from the following specifications and drawings, the following of which is a brief description.